PSI - Issue 14

Ritesh Dadhich et al. / Procedia Structural Integrity 14 (2019) 104–111 R. Dadhich, A.Alankar / Structural Integrity Procedia 00 (2018) 000–000

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microstructure consisting of inclusions has been compared with the results from DAMASK, an open source crystal plasticity simulation package developed by Roters et al. (2012). Noteworthy is that the stress field from both the models are qualitatively comparable. The major difference in results is that the stress field from DAMASK has more fluctuations as compared to the current model which could be due to the difference in the way FFT solutions are used. In the other simulation, inclusions are replaced by the voids having very low stiffness values with same homogeneous medium as in the previous case. Fig. 2(c and d) shows the variation of stress along the dashed line on the mid-plane (Fig. 2(a)) for the simulation having inclusions and voids respectively.

Fig.2. Stress σ 33 distribution on XY mid plane having two inclusions in a homogenous pure aluminum medium by (a) present model and (b) DAMASK simulation. Variation of stress σ 33 along the dashed line in case of (c) hard inclusions, (d) voids.

Fig. 3. (a) Concentration profile on a XZ mid plane; (b) Evolution of concentration, when a hard inclusion is at the center.

For microstructure evolution problem, the CPFFT code has been modified to get the evolution of conserved field variable using modified Cahn-Hilliard equation. The modified code is then tested by running the simulation for a homogeneous medium with a spherical void at its center as given in Fig. 3(a) and the external strain up to 0.001 is